1. Field of the Invention
This invention relates to a slider for a fluid tight fastener.
2. Description of the Related Art
Examples of such a fluid tight fastener are described in EP-A-1057423 and EP-A-1175842. In such a fluid tight fastener, a coil like continuous coupling member is sewn onto a tape surface near an edge of the tape. The other surface of the tape is coated with a fluid proof layer which extends beyond the edge of the tape to form a sealing lip. When the coupling members of adjacent tapes are engaged, the sealing lips of the fluid proof layers abut to form a seal. Such fasteners can provide a reasonably good seal against liquids or gasses, depending on various factors such as the design of the sealing lips of the fluid proof layers, the extent to which they are urged together by the coupled elements and the extent of flexing of the fastener in use.
The slider shown in EP-A-1057423 and EP-A-1175842 incorporates a guide plate or “guide flange” in the form of a thin blade which projects from the wedge which joins the upper and lower plates of the slider. This guide plate extends between the outer ends of the coupling elements and the sealing lips. Thus the guide plate creates upper and lower paths within the slider and serves to ensure more accurate alignment of the coupling elements as they are brought together and enables greater pressure to be exerted on the sealing lips whilst keeping them aligned.
In practice, the slider shown in EP-A-1057423 and EP-A-1175842 has been made of three parts, with the guide plate being formed separately and sandwiched between the upper and lower plates and guide posts. This adds significantly to the cost of the production process.